Resource and hardware options for microarray-based experimentation.

DNA microarray technology permits the study of biological systems and processes on a genome-wide scale. Arrays based on cDNA clones, oligonucleotides and genomic clones have been developed for investigations of gene expression, genetic analysis and genomic changes associated with disease. Over the past 3-4 years, microarrays have become more widely available to the research community. This has occurred through increased commercial availability of custom and generic arrays and the development of robotic equipment that has enabled array printing and analysis facilities to be established in academic research institutions. This brief review examines the public and commercial resources, the microarray fabrication and data capture and analysis equipment currently available to the user.     

THE LACK OF CHLOROPLAST DNA IN ACETABULARIA MEDITERRANEA (ACETABULUM) (CHLOROPHYCEAE): A REINVESTIGATION1

Three features of chloroplast DNA (cpDNA) in plastids isolated from Acetabularia mediterranea (acetabulum) were analyzed after staining the organelles with the fluorochrome 4′6-diamidino-2-phenyl indole (DAPI): (1) number of chloroplasts exhibiting DNA fluorescence, (2) number of nucleoids per plastid, and (3) nucleoid morphology. In vegetative Acetabularia cells only half of the total chloroplast population comprising several millions displayed the whitish-blue fluorescence of the DNA/DAPI complex. This percentage remained stable independent of whether cells were grown in supplemented natural sea water or enriched synthetic sea water. A single nucleoid, widely differing in size and morphology among the organelles, was characteristic of 76–81% of chloroplasts with DNA. Less than 20% contained two nucleoids, and in rare cases three or four nucleoids were present. The pattern of nucleoid numbers followed a Poisson distribution in one experiment, if calculated with the intrinsic mean of the observed data. In two other experiments, however, a significant difference existed between observed and expected values for a Poisson distribution according to the Chisquared test. After secondary enlargement of portions of the negatives, the nucleoids’substructure was disclosed and found to consist of brightly fluorescent spots interspersed by unstained regions The lack of cpDNA in Acetabularia cells appears to be brought about by (1) the polarized pattern of growth and translation confined to the apical region of the single cell and (2) the cpDNA arrangement in a single nucleoid acentrically located in the organelle. A scheme for the evolution of a chloroplast population having plastids without DNA is proposed. In theory the lack of cpDNA could arise in each plant, since chloroplasts never evolved a mitotic-like spindle to ensure the equal distribution of genetic material. The different nucleoid arrangement in most other plants, however, efficiently counteracts this ‘carelessness of nature’     

猕猴属6个种的rDNA变异及其系统进化关系

以人２８Ｓ,１８Ｓ,ｒＤＮＡ为探针,用１５种限制性内切酶构建了猕猴属６个种（Ｍ．ｍｕｌａｔｔａ,Ｍ．ｆａｃｓｉｃｕｌａｒｉｓｆＭ．ａｒｃｔｏｉｄｅｓ,Ｍ．ａｓｓａｍｅｎｓｉｓ．Ｍ．ｔｈｉｂｅｔａｎａ．Ｍ。ｎｅｍｅｓｔｒｉｎａ）和滇金丝猴Ｒｈｉｎｏｐｉｔｈｅｃｕｓｂｉｅｔｉ）,白颊长臂猿（Ｈｙｌｏｂａｔｅｓｌｅｕｃｏｇｅｎｙｓ）核糖体ＤＮＡ重复单位的限制性内切酶图谱,红面猴（Ｍ．ａｒｃｔｏｉｅｓ）与     

Interaction of synthetic peptide corresponding to signal sequence of glucitol permease of Escherichia Coli and its analogue with liposomes

The N-terminal signal sequence of glucitol pcrmease of Escherichia Coli (Gut22) and its analogue (Gut22Ana) were synthesized. The analogue had a Pro residue substituting for the His at the 7th position of Gut22 and a Val residue substituting for the Glu at the 10th position. The intrinsic fluorescence emission spectra indicated that the binding of Gut22 with lipid bilayer was much stronger than that of Gut22Ana. The leakage experiments with calcein-loaded liposomes showed that Gut22 strongly perturbed lipid bilayers while Gut22Ana did not. The apparent partition constant of Gut22 for partitioning into phosphatidylserine/phosphatidylcholine bilayers was measured; the effect of membrane potential on the interaction of Gut22 with lipid bilayers was studied and the conformation changes of Gut22 and Gut22Ana upon interacting with liposomes were studied by the method of circular dichroism analysis.     

红原鸡与家鸡的亲缘关系研究

对中国红原鸡滇地亚种和海南亚种与我国茶花鸡,泰和鸡和寿光鸡等地方鸡种以及芦花鸡,洛岛红等外国鸡种进行了血型（３个位点,１３个等位基因）,蛋白质（酶）多态（５个位点,１１个等位基因）和ＤＮＡ指纹分析,结果表明,红原鸡与茶花鸡（原始型品种）的亲缘关系较近;与泰和鸡,寿光鸡,芦花鸡,洛岛红（进化型品种）的亲缘关系较远,呈红原鸡－茶花鸡－泰和鸡,寿光鸡或芦花鸡,洛岛红这样一个进化阶梯,以上结果与国外资料（     

Molecular markers of nuclear restoration gene Rf1 in sunflower using bulked segregant analysis-RAPD

Restoration of cytoplasmic male sterility (CMS) in sunflower was demonstrated to be controlled by polygenes by analysing 982 effective crosses among 109 self-crossed lines and 16 CMS lines. Two self-crossed lines and one CMS line with distinct genotypes were applied to creation of segregating populations for DNA bulks of the target gene Rfl. Bulked DNA was prepared in order to investigate single gene Rfl and its gene marker among polygenic characters at the same genetic background. Using 80 10-mer operon primers, 620 RAPD reactions were carried out between fertile and sterile DNA bulks. In about 800 loci, primary results showed that 8 were related to the restoration genes. Furthermore. 2 were confirmed as RAPD markers for gene Rfl by examining 9 maintenance and 7 restoration lines. This method is the improvement for bulked segregant analysis[1] with which markers of single gene of target can be identified rapidly among polygenic characters.     

Exploiting the complete yeast genome sequence

The completion of the genome sequence of the budding yeast Saccharomyces cerevisiae marks the dawn of an exciting new era in eukaryotic biology that will bring with it a new understanding of yeast, other model organisms, and human beings. This body of sequence data benefits yeast researchers by obviating the need for piecemeal sequencing of genes, and allows researchers working with other organisms to tap into experimental advantages inherent in the yeast system and learn from functionally characterized yeast gene products which are their proteins of interest. In addition, the yeast post-genome sequence era is serving as a testing ground for powerful new technologies, and proven experimental approaches are being applied for the first time in a comprehensive fashion on a complete eukaryotic gene repertoire.     

Low frequency of extra-pair paternity in two colonies of the socially monogamous short-tailed shearwater Puffinus tenuirostris

The short-tailed shearwater is a colonially nesting, socially monogamous seabird. Little is known about mate fidelity and breeding behaviour in this species because breeding birds are nocturnal on land and spend much of their time within subterranean nesting burrows. Colonial breeding and extended sperm storage create opportunities for extra-pair copulations which may form a significant component of the mating strategy in this species. Multilocus DNA fingerprinting was used to examine the genetic relationship between nestlings and the male and female nest attendants in 83 burrows from two distinct breeding colonies. Genetic analyses identified nine nestlings, approximately equally distributed between the two colonies, that were not related to the attendant pair male in those burrows, implying extra-pair paternity through extra-pair copulations. These results are used retrospectively to discuss the characteristics of extra-pair copulations and extra-pair fertilizations and the implications for estimates of life-time reproductive success in the short-tailed shearwater.     

Homology among RAPD fragments in interspecific comparisons

The use of RAPDs for comparative purposes relies on the assumption that similarity of fragment size is a dependable indicator of homology. To test the validity of this assumption, homology among 220 pairs of comigrating fragments from three wild sunflower species was determined. Ninety-one per cent cross-hybridized and/or displayed congruent restriction fragment profiles suggestive of homology. However, comparative linkage mapping data indicated that 13% of the homologous loci mapped to genomic locations that were incongruent with the majority of loci, suggestive of paralogous rather than orthologous relationships. Thus, of the 220 pairwise comparisons, only 174 (79.1%) identified loci that are useful for comparative genetic studies. These problems, as well as several other factors discussed in the text, will introduce noise into RAPD data sets and thereby reduce the probability of generating accurate estimates of genetic relationships. Recommended methods for reducing noise in RAPD data sets include increasing gel resolution and/or testing fragment homology. However, implementation of these approaches will not eliminate all uncertainties, and it is also recommended that RAPD data sets be tested for structure and reliability.